Course device for vehicles



Get. 31, 1939. I cK I 2,178,365

COURSE DEVICE FOR VEHICLES Filed June 25, 1937 Patented Oct. 31, 1939 COURSE DEVICE FOR VEHICLES I Friedrich Lauck, Beriinspandau. Germany, as-

signor to Siemens Apparate und Maschinen Geselischaft'mit beschrinkter Haftnng, Berlin, Germany, a corporation of Germany Application June 25, 1937, Serial No. 150,415 In Germany June 29, 1936 2 Claims. (01. as-z24) This invention relates to course maintaining devices for vehicles, such as aircraft, and more particularly to devices of the above type which include means responsive to theearths magnetic field and are adapted to indicate direction or to control the course of the vehicle.

An object of the invention is to provide a device of the above type which is automatically corrected to compensate forthe compass devia- -10. tion caused by the metallic parts of the vehicle itself.

- Another object is to provide a device of the above type having means to correct the compass variation due to the known angular variation in 16, the earth's magnetic field. i Other objects and advantages will. be apparent as the nature of the invention is-more fully dis- I closed.

Although the novel features which are believed 20 to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself may berbetter understood by referring to the following description, taken in connection with the accompanying 5 In the following description and in the claims certain specific terms are used for convenience in referring to various details of the invention; It is to'be understood, however, that these terms are to be given as broad, an interpretation as 49 the state of the art will permit.

Referring to the embodiment shown in Fig. 1, a compass i is disclosed which may be of any standard type having a directional element responsive .to the earth's magnetic ileld mounted in cooperss ative relation with acourse member such as a compass card and whichcompass is suspended-by links 2 and 3 from a shaft 4 in such manner.

that the compass at all times remains horizontal. Adisc 5 is carried by the shaft l and is provided 50 at its periphery with teeth which are engaged by a pinion 6, attached to a'lever I. The lever i carries a roller 8, engaging a'cam disc 9, which is fixed'with respect to the vehicle. The'pinion 6 is carried on a worm wheel I. which is coss anal with the shaft 4 and is coupled with the- Qua:

disc 5 by means of a spring II which is adapted to take up any slack or looseness between the disc I and the pinion 6 and to hold the roller 8 against the surface of the cam disc 9.

The worm wheel it is adjusted by means of a 5 worm l2, carried by a shaft l3 and controlled by a crank it .actuating a shaft l3a, which is connected to the shaft II by means of a differential gear II. The differential gear l'l comprises a disc ila attached to the shaft l3 anda 10 sleeve l'lb journalled on the shaft l3a,..said disc 20, is actuated by a worm Isa mounted on a shaft lie to indicate the adiustment effected by the crank it.

In the operation of the above. described device the desired course is set by adjustingthe course member by means of the crank it and the scale. It. This adjustment is eifected by. the unitary movement of the shafts l3 and lid which, through the worm i2 and the worm wheel iii" and pinion 6, cause a corresponding movement of the disc 5, thereby displacing the housing of the compass i and setting the compass to the course desired. During this adjustment the roller 8 rolls around the surface of the cam disc 8. therebycausingthe pinion 6 to rotate slightly and to vary the angular position of the disc 6 by an amount dependent upon the contour of the cam disc 9. The cam disc 8 is designed to compensate for the-deviation caused by the vehicle itself, such as by the distribution of the magnetic masses which affect the accuracy of 'desired angular position-by means of the scale it. Thereafter 'it is only necessary to make the neceasarv adiuatment'according to the scale I.

to compensate for the variation of the compass at the particular localities involved. Hence all mental calculations are eliminated and the accurate adjustment of the compass to the desired -course is facilitated.

; in a gimbal ring 24 by means of a precession shaft.23 which is perpendicular to the axis of rotation of the gyroscope. The gimbal ring 24 is mounted on a shaft 25 which is perpendicular to the shaft 23 and is carried in'suitable bearings (not shown). A permanent magnet 25 is mounted on the shaft 23 in the field of an electromagnet 21.

A disc 28 is mounted on the shaft 25 and carries a pinion 29 having teeth engaging the periphery of a' toothed disc 33. The pinion 23 is attached to a lever 30 carrying a roller 3! which engages the surface of a stationary cam disc 32. The toothed disc 33 is mounted on a sleeve 34 which is rotatable with respect to the shaft 25. A spring 35- interconnects the disc 28 and the toothed disc 33 so as to eliminate lost motion and to hold the roller 3| against the surface of the cam disc 32.

A double contact arm 36 is mounted on the sleeve 34 and engages a resistance unit 31 which is suitably connected by leads 31a to a similar resistance unit 38 with which a second double contact arm 33 is ii -contact. The double contact arm 39 is actuated by astandard compass 40 so as to assume a position according to the position of the compass needle.

The resistance unit 31 is mounted on a worm wheel 4| which is engaged by a worm 42 mounted on a shaft 42a and actuated by a crank 43. A scale 44 may be mounted on the shaft 424 and maycooperate with an index mark 45 to indicate the adjustment eifected by the crank 43..

The lower end of the shaft 25 carries a contact arm 45 which is adapted to make contact. with contact members 41 and 43 carried by a disc 43. The disc 43 carries a worm gear which is actuated by a worm 50 carried by a shaft and controlled by a crank 52. A scale 53, cooperating with an index mark 54, may be driven by a worm 53a mounted on the shaft 5| to indicate the adjustment effected by the crank 52. The electromagnet 21 is connected by leads 21b with the the relative angular displacement between the arms 35 and 35 and becomes zero when the arms 35 and 35 are in the same relative angular positions. This voltage is impressed upon electromagnet 21 and thereby produces a field which, acting ,upon the permanent magnet 25, produces a torque on the precession shaft 23 in a direction such that the precession eifect of the gyro causes the shaft 25 to rotate. This rotation of the shaft 25- continues until the angular position ofthearmflcorrespondstothatofthearmu.

It will be noted, however, that the shaft 25 and the sleeve 34 are interconnected by the cam disc 32 and roller 3|, similar to the cam disc 3 and roller 5 of Fig. l, which are designed to compensate for the compass deviation produced by the craft itself. The shaft 25 is accordingly caused to assume a position which corresponds to the angular position of the compass 45 corrected for such deviation. The directional variation may be compensated for by suitable adjustment of the crank 43 which causes rotation of theworm wheel 4| and the resistance unit 31. In'this embodiment the course may be set by means of crank 52 which causes suitable displacement of the course member comprising disc 49 which is thereby displaced with respect to the arm 46 held in position by the gyro controlled by the compass 40. Any change in the direction of the vehicle from this course, through the mechanism above described, causes the arm 45 to make contact with the contact members 41 or 48 and thereby to complete a circuit to a suitable mechanism, not shown, for indicating or for correcting such change,

It will be noted' that the systems above described provide an accurate means for automatically correcting the deviation of the compass needle without introduction of magnetic masses or other correcting means which tend to distort the direction of the earths field. Means is also provided so that the variation of the compass can be easily corrected by 'the navigator. In operation it is only necessaryto make two adjustments, namely, the course adjustment effected in accordance with scale l5 of Fig. 1 or the scale 53 of Fig. 2, and the variation adjustment which is effected in accordance with the scale IQ of Fig. 1 or the scale 44 of Fig. 2.

Although certain specific embodiments of the invention have been shown for purposes of illustration, it is to, be understood that various changes and modifications may be made therein as will appear to a person skilled in the art. The invention is only to be limited in accordance with the following claims when interpreted in view of the prior art.

What is claimed is:

1. A course maintaining device for vehicles comprising a magnetic directional element responsive to'the-earths field, a shaft, a directional gyro connected to said shaft, electrical means connecting said magnetic means and gyro whereby said gyro is caused to precess to remain in a position approximately relatively fixed with respect to the position of said directional element, means to modify said relatively fixed position in accordance with the deviation of said directional element, comprising a disc connected to said shaft, a second disc connected to said electrical means, means resiliently connecting said first and second discs, a fixed cam having a contour corresponding to the deviation of said directional element and means attached to one of said discs and connected to the other disc and engaging said cam to relatively rotate said discs as the shaft turns, whereby the position of the other of said discs is varied upon movement of the gyro to vary the effect of said electrical means whereby said relatively fixed position is modified in accordance with the deviation of said directional element.

- 2, A course maintaining device for a vehicle .comprising a magnetic compass, a gyro, a course. member in cooperative relation with said gyro. mans responsive to variations in the positions ment in azimuth therewith. and cam means fixed to said vehicle and controlling saidpinion so as to vary the relative position of said first disc in accordance with the known deviation of said compass.

FRIEDRICH LAUCK. 

